Major fuel system components used in vehicles for delivering fuel to an internal combustion engine include an engine, a common rail, fuel lines, a fuel pump, and a valve disposed in a fuel line between the engine and the fuel pump.
While current fuel systems have generally proven to be satisfactory for their applications, each is associated with its share of limitations. One major limitation with many current fuel systems relates to the delivery of fuel from the fuel pump to the engine. More specifically, in a multiple fuel pump arrangement, when the pumping action of one of the pumps is compromised, current valves are incapable of completely terminating fuel flow to the engine. This presents a fuel supply situation in which the air to fuel ratio to the engine is compromised, which results in less than optimal combustion such as lean burn combustion.
Another limitation of current multiple fuel pump fuel systems is their inability to maintain fuel flow, after the failure of one pump, only to the extent necessary to maintain combustion and permit a vehicle to travel in order to move or to receive service. The inability of dual fuel pump fuel system valves to offer this feature results in vehicle engines that are incapable of operating in order to permit a vehicle to move off of a roadway or reach service.
What is needed then is a device that does not suffer from the above limitations. This in turn will provide a device that eliminates the problem of fuel flowing through a fuel valve from a first fuel pump of a dual fuel pump arrangement when a second pump ceases to operate, thereby preventing an engine from operating under a less than optimal combustion condition such as lean burn combustion. Furthermore, a device will be provided to successfully stop the flow of fuel from all fuel pumps of a multiple fuel pump arrangement when any of the pumps ceases to operate. Additionally, it is desired that in the event of a failure of a first pump in a dual fuel pump arrangement, the device will permit the second pump to discharge just enough fuel to the engine to support combustion to permit a vehicle to move.